Abstract
A cubic Mn_(0.6)Fe_(0.4)S solid solution material has been synthesized using a scalable in situ sulfuration treatment of Prussian-blue analogs (PBAs), and its phase formation process and Li-storage mechanism were investigated. Increased treatment temperature and time encourage a phase transformation from hexagonal Fe_7S_8 to cubic FeS_2 during the sulfuration process, which results in the formation of a solid solution between cubic FeS_2 and cubic MnS. The resulting Mn_(0.6)Fe_(0.4)S solid solution electrode exhibits high initial coulombic efciency, excellent rate performance, and superior cycling stability (520 mA h g~(-1) after 1000 cycles at 1.0 A g~(-1)). Ex-situ X-ray diffractometry and electro-kinetics tests show that the doping-induced structural phase transition in Mn_(0.6)Fe_(0.4)S solid solution creates a favorable electronic structure and ensures rapid charge transfer kinetics during the lithiation/delithiation process, simultaneously achieving high energy conversion efciency and a long lifespan.
NSTL
Elsevier